[BBC News] A consultation on expanding airports in south-east England has been delayed again amid reports of tensions within the coalition over the issue.

Waiting: Planes queue for take off at London City Airport – congestion could increase air fares.

The consultation had been due to be announced later but is now unlikely to go ahead until the autumn.

The Lib Dems are opposed to expansion, and the coalition agreement rules out new airports in the region. But there is speculation that Chancellor George Osborne is warming to the idea of a third Heathrow runway.

Several Tory MPs are also openly supporting the plan, says BBC transport correspondent Richard Westcott. They have been accused of trying to delay everything until after the next election, when they believe they could be in power as a single party.

It is another delay for a consultation that was meant to start in March, then delayed until the summer, and is now likely to wait until the autumn. It was dealing with some of the thorniest issues in aviation, including whether to build a third runway at Heathrow airport in west London, or perhaps build extra runways at Stansted or Gatwick. Some concerns have been expressed about the environmental impact of a third runway at Heathrow and the potential for it to damage people’s quality of life.

Conservative MP Zac Goldsmith, a well known environmentalist, said he would not stand as a candidate for the party at the next election if it supported a third runway.